list rows: Set accessible roles

Set accessible roles

spin-row

Downgrade accessible role to presentation.

We already contain a spin button which is accessible on its own, automatically focused, and usable like any other spin button. This already behaves exactly like spin button.

Previously the value would be read three times, first as text, then as label, then as spin button.

switch-row

Set accessible role to switch.

We don't allow to focus the switch itself, so we should inherit its role.